FR2905436A1 - CURRENT RING AND FIXED WINDING TYPE ELECTROMAGNETIC CLUTCH DEVICE, AND MULTIPLE OUTPUT MECHANICAL TRANSMISSION MECHANISM COMPRISING AT LEAST ONE SUCH DEVICE. - Google Patents

Abstract

- The device comprises a mechanical input member (1) by which the driving power is supplied, two output shafts (A, A ') coaxial and on the ends opposite which the mechanical input member (1) is rotatably mounted, each output shaft (A; A ') having an electromagnetic clutch which comprises a magnetic circuit (5) mounted on the corresponding output shaft, comprising: - a fixed part (8) in which is housed the winding (9), and- a movable part (7), integral in rotation and free in translation relative to the output shaft, moving towards the mechanical input member (1) to be driven by it ci when the coil (9) is energized, and thereby acting as a movable clutch plate to rotate in solidarity the mechanical input member (1) and the corresponding output shaft (A) .- Motor vehicles. Clutch devices. Geared motors for the control of car accessories.

Description

DOUBLE ELECTROMAGNETIC CLUTCH DEVICE OF THE RING AND A TYPE

  FIXED WINDING, AND MULTIPLE OUTPUT MECHANICAL TRANSMISSION MECHANISM COMPRISING AT LEAST ONE SUCH DEVICE.

  The present invention relates to a dual electromagnetic clutch device of the ring type and fixed winding. It also relates to a mechanical transmission mechanism 10 with several outputs comprising at least one such clutch device. According to Japanese Patent Application No. 2000205303, an electromagnetic clutch of the revolving coil type is known in which a coil is placed on a rotor so as to be electrically isolated. In this clutch is provided a sliding mechanism carrying current, which comprises collecting rings and brushes which are mounted sliding contact on the collecting rings. Through the current-carrying sliding mechanism, the coil is supplied with current, and the collecting rings are held by the rotor via a collector ring holding member, while the brushes are held by a boss portion via a brush holding member. The broom on the negative electrode side is grounded so that it comes into direct contact with the boss portion; therefore, it is not necessary to have a cable extension for grounding. The structure 30 is simplified. According to US Pat. No. 4,257,508 there is known a low weight electromagnetic clutch which can be used with an air conditioning compressor and which comprises a rotating electromagnetic coil, a pulley device and a reinforcing plate, so as to form a magnetic flux circuit. A curved (or trim) shaped annular member 2905436 is added in a back-to-back position with a rotating coil housing to provide a controlled structure carrying a unitary flow, the outer radial portion of each of the two defining members a groove for receiving a driven pulley belt. The inner radial portion of the domed-shaped member, the inner wall of the spool housing and a tubular extension attached to the support housing define a bearing cavity in which the domed-shaped member and the shaped support provide, with the coil housing, compound flux paths for the magnetic circuit. The object of U.S. Patent No. 6,012,563 seeks to reduce the axial dimension of a coil-type electromagnetic clutch and to extend the life of its brushes. For this, the clutch comprises a sliding power supply mechanism, with collecting rings and sliding brushes in contact with the collecting rings, which is located inside a boss, so as not to increase the dimension of the set in the axial direction. Further, since the power supply mechanism is located near the center of rotation of the clutch, the life of the brushes is increased because their peripheral linear speed is low.

  According to US Pat. No. 6,169,347 B1, an electromagnetic clutch is also known in which the coil is disposed in a rotor and electrically isolated from the rotor. A slip ring is supported by a rotor through a ring holder, and rotates with the rotor. A broom is supported by a compressor boss portion via a brush holder, and provides electrical power to the slip ring. A diode is housed in the brush holder or ring holder, and absorbs the overvoltage that is induced when the electromagnetic coil is de-energized. The surge absorption element 2905436 3 does not increase the axial dimension of the electromagnetic clutch. According to US Pat. No. 6,298,967 B1, an electromagnetic clutch is also known in which the electromagnetic coil is fixed in a rotor by means of an insulating member. A collector ring rotating with the rotor and a power supply brush of the ring are radially disposed within a bulging portion of the compressor housing. The collector ring is attached to the rotor via a ring holder and the sweeper is held by the bulge portion via a brush holder. The wiper support 15 comprises a cylindrical sleeve mounted radially inside the wiper, which extends axially outwards further than a sliding surface between the collecting ring and the wiper blade. Accordingly, electromagnetic clutch devices, mainly with a rotating coil, in which attempts have been made to reduce dimensions and / or weight, are well known. The object of the present invention is to improve such devices, known from the prior art, by providing a double electromagnetic clutch ring and fixed winding device, simpler construction, even more compact configuration, more robust and more reliable. Another object of the present invention is to provide such a clutch device which is as compact as possible in the axial direction of the device and in which the input drive wheel is guided over a reduced axial distance. It is also an object of the present invention to provide such a clutch device, able to integrate optimally into a mechanical transmission mechanism comprising an input with an electric actuator, and a plurality of outputs between which is distributed the input power. To achieve these aims, the present invention provides a novel electromagnetic clutch device which is of the fixed ring and coil type, which includes a mechanical input member through which the driving power is supplied, two coaxial output shafts. and at the ends opposite which the input mechanical member is rotatably mounted, each output shaft having an electromagnetic clutch for providing or disengaging the power transmission of the input mechanical member to the output shaft. Each clutch comprises: a magnetic circuit, mounted on the output shaft, comprising a part fixed in rotation and in translation, in which is housed the electromagnet coil and a movable part, integral in rotation with the output shaft and movable in translation under the effect of the electromagnetic force generated when the coil is energized, - said moving part of the magnetic circuit moving towards the mechanical input member to be driven by it when the coil is fed, and thus acting as a movable clutch plate for securing in rotation the mechanical input member and the output shaft. According to a preferred embodiment of the invention, the mobile part of the magnetic circuit has the shape of an annular plate with wide recesses, so as to reduce the magnetic flux passing surface between the fixed part of the magnetic circuit and the surface facing the mechanical input member. Preferably, the movable portion of the magnetic circuit is rotatably mounted to the output shaft by means of two opposite splines. In one embodiment of the invention, the two coaxial output shafts opposite are identical.

In a variant, the two output shafts are coaxial, but are not identical, the male end of one of the two output shafts being rotatably mounted in the female end of the other output shaft. in order to reduce the axial dimension of the mechanical input member. According to an advantageous embodiment of the invention, the two output shafts comprise a central short bore identical to their end in view, in which a single bar is housed to stiffen the device and reduce the guiding distance of the mechanical input member. This bar is cylindrical, preferably, when the two shafts must be detached. It may not be cylindrical in cases where the coupling of the two shafts is a permanent coupling. In addition, the opposite ends of the one and the other output shaft have a square section housing, so as to accommodate a flexible tube containing a square section cable. The fixed part of the magnetic circuit may advantageously be surmounted by a peripheral ring, so as to allow its integration into a housing.

The mechanical input member may preferably be an input wheel. It can also be a pulley, or a friction drive mechanism. The present invention also relates to a new mechanical transmission mechanism with several outputs or geared motor, which comprises: a first module consisting of a double ring cone and fixed coil electromagnetic clutch device, in accordance with FIG. that which has just been described in outline, 35 - a second module comprising an electric actuator and a clutch module unit, and 2905436 6 - a third module with two outputs with a single clutch. Other objects, advantages and features of the invention will become apparent from the following description of a preferred, non-limiting embodiment of the object and scope of the present patent application, accompanied by drawings in which: FIG. 1A is a sectional view of a first embodiment of the electromagnetic clutch device according to the present invention; FIG. 1B is a front view of the moving part of the electromagnetic mechanism of the embodiment of the invention. FIG. 2 is a diagram illustrating different magnetic flux line paths in the magnetic circuit of the electromagnetic clutch of FIGS. 1A and 1B, FIG. 3A is a sectional view, in accordance with FIG. IIIA-IIIA line of FIG. 3B, a second embodiment of the electromagnetic clutch device, according to the present invention; FIG. 3B is a front view of the electric clutch device; Fig. 3C is a perspective view of the electromagnetic clutch device of Figs. 3A and 3B, Fig. 4A is a sectional view of a third embodiment of the electromagnetic clutch device. According to the present invention, FIG. 4B is an enlarged view of the central portion - referenced B in the drawing of FIG. 4A - of the electromagnetic clutch device of FIG. 4A, FIG. 5A is a sectional view. of a fourth embodiment of the electromagnetic clutch device according to the present invention; FIG. 5B is a front view of the electromagnetic clutch device of FIG. 5A; FIG. 5C is a perspective view. 5A and 5B, and FIG. 6 is a diagram illustrating the general configuration of a mechanical transmission mechanism both an electromagnetic clutch device according to the present invention. In the drawing of FIGS. 1A and 1B, there is shown a first embodiment of the electromagnetic clutch device according to the present invention. The device constitutes a mechanism for mechanical transmission of a driving power to two power outputs, S1 and S2, each output being equipped with an electromagnetic clutch. Such a dual clutch mechanism is intended to be integrated in a multiple output device (more than two outputs). Such a multiple-output device may be, for example, a geared-type device for distributing mechanical power between several outputs, each output (or some of them) comprising an electromagnetic clutch intended to establish or to defeat, on command, the transmission of part or all of the motive power to this output.

The part referenced 1 is, in general, a mechanical input transmission member, through which a mechanical power is supplied. This member may be a toothed wheel, as in the embodiments described below as non-limiting examples of the object of the invention, or a pulley, or a friction drive mechanism, by example. This mechanical input member 1 is permanently connected to another mechanical transmission member (for example, another gear wheel not shown) connected to the output shaft 35 of a motor (not shown). The toothed wheel 1 is mounted free to rotate on the ends, 2 and 2 ', of two output shafts, A and 2905436 8 A', coaxial, identical, and in the extension of one another. In the remainder of this text, only the transmission part located in the left part of FIG. 1A, that is to say the transmission part between the wheel 1 and the output shaft A towards the output, will be described. S1. The portion relating to the output shaft A 'to the output S2 is, mutatis mutandis, similar to that relating to the output shaft A to the output S1.

On a part referenced 6 of the output shaft A (6 'for the shaft A') is mounted the electromagnet mechanism of the electromagnetic clutch, general reference 5. The electromagnet mechanism 5 comprises a translational portion 7 and a portion 8, which is fixed relative to the frame of the mechanism (not shown). The movable part 7 - or annular piece or ring - is mounted integral in rotation with the output shaft A by means of two grooves whose grooves are shown at 11 (see Figure 1B), for example. On the fixed part 8 is fixedly mounted the coil 9 of the magnetic circuit. When the coil 9 is energized, a magnetic field is produced, the moving part 7 is displaced in translation, and is then rotated by the toothed wheel 1, via the ferromagnetic ring 10 rigidly fixed on the lateral surface opposite the toothed wheel 1. Consequently, the output shaft A is made integral in rotation with the toothed wheel 1, by means of the movable part 7 integral in rotation with the drive shaft. When the coil 9 is energized, a magnetic flux is generated in the magnetic circuit formed by the electromagnet mechanism 5 and the ring 10. This magnetic flux is likely to follow two distinct paths, as shown in FIG. schematically in the drawing of Figure 2. The circulation of the field lines 2905436 9 along the designated path T1 in Figure 2 does not cause displacement of the slider 7, because such Field lines do not meet an air gap. By contrast, in contrast, the field lines along the designated path T2 meet two air gaps. It is therefore advantageous that a maximum number of field lines follow the path T2, which is a source of displacement of the sliding part 7. In order to limit the magnetic flux passing through the path T1, the passage surface must be reduced. , that is to say the driving surface of the sliding part 7. It is for this reason that the mobile part 7 has in its contact part referenced 7b a very openwork configuration. Indeed, as can be seen in the drawing of Figure 1B, the connecting wall 7b of the movable portion 7 is made with wide recesses. By way of non-limiting example of the object of the invention, the connecting wall 7b is made with four recesses, referenced El to E4, which leave a contact surface between the parts 7 and 10 minimum, formed by radii narrow, designated ri to r4, and two narrow rings, namely an inner narrow ring Ci and an outer narrow ring Ce. Note that the number of narrow radii, and their angular distribution is of no importance on the electromagnetic operation of the device: it is only a question of ensuring the connection and good mechanical strength between the outer and inner rings. It should also be noted that the peripheral portion 7a of the movable portion 7, as well as the hub portion 7c, are both closer to the surface 10 than the contact portion 7b. The gap distances are designated x and x + y for part 7a and part 7c, respectively. As previously mentioned, narrow radii r4 to r4 - or radial bands - have only a function of mechanical strength of the outer ring relative to the axis. In the present embodiment of the invention, the sidebands are dimensioned so as to lose the minimum of force at the clutch (any flow through the radial strips can no longer be used to contribute to the force. at the level of the clutch). Note also that it would be possible, alternatively, to connect the ring to the axis by a magnetically nonconductive material, and thus avoid recesses. But in the present embodiment, the annular piece 7 is made of a single material; which provides cost and manufacturing advantages. When the coil 9 is energized, the bulk of the magnetic flux flows along the path T2, the moving part 7 moves against the lateral surface of the ring gear 10 of the toothed wheel 1. This contact is made at the periphery of the ring gear 10 To ensure a good sliding pivot connection between the bore of the input wheel 1 and the end of each output shaft A, A ', the dimensional constraint expressed by the following relation must be respected. L> 1.5 D in which L (see FIG. 1A) is the length of the end 2, respectively 2 ', of the output shaft A, respectively A', and D is the diameter of the end 2 of the output shaft A and the identical end 2 'of the output shaft A'. For this reason, the toothed wheel 1 of Figure 1A has a relatively large thickness V. In other words, the toothed wheel 1 is guided over a relatively large guide distance V. An attempt has been made to reduce this thickness V by modifying the structure of the ends 2, 2 'of the output shafts A, A', respectively, as shown in the drawing of FIGS. 3a to 3C.

The elements of FIGS. 3A to 3C, which are identical to those of FIGS. 1A and 1B, bear the same reference numerals. Thus, with reference to FIG. 3A, the toothed wheel 5 1 is in connection with another toothed wheel (not shown) connected to the output shaft of an engine (not shown). The toothed wheel 1 is mounted idly on the cylindrical assembly of the two ends, 20 and 20 ', of the two output shafts, A and A', respectively. Both ends 20 and 20 'are coaxial but, unlike the configuration described above, are not identical and are not in line with one another. The end 20 'of the output shaft A' is a male cylindrical part which is engaged in the end 15 of the output shaft A. The end 20 is a female part in the form of a cylindrical sleeve of diameter inner diameter equal to the outer diameter of the male portion 20 ', with sufficient clearance to allow the relative rotation of 20 relative to 20'.

On a part referenced 6 of the output shaft A (6 'for the shaft A') is rotatably mounted the electromagnet mechanism of the electromagnetic clutch, general reference 5. The mechanism of electromagnet 5 comprises a part movable in translation 7, similar to that of the device described above with reference to FIGS. 1A and 1B, and part 8, which is fixed (in translation and in rotation) with respect to the frame of the mechanism ( not shown). On the fixed part 8 is fixedly mounted the coil 9 of the magnetic circuit 30. When the coil 9 is supplied with electrical current, the moving part 7 of the electromagnet mechanism 5 is moved in translation, and then comes into contact with the lateral surface opposite the ring gear 10 of the gear wheel 1, making thus rotating the toothed wheel 1 and the moving part 7 of the electromagnet mechanism, and thus making the toothed wheel 1 and the output shaft A integral, in rotation with the mobile part 7, fixed. The output shaft A is then in the engaged position. The configuration thus described with reference to the drawings of FIGS. 3A to 3C makes it possible to reduce the thickness of the toothed wheel 1. However, this thickness, designated U, is still significant and moreover, in this configuration, the ends of the two shafts are different; This results in the manufacture of an additional piece with respect to the configuration described with reference to the drawings of FIGS. 1A and 1B in which the two ends are identical. The embodiment described with reference to the drawings of FIGS. 4A and 4B is intended to further reduce the thickness of the toothed wheel 1, therefore the guide distance of the toothed wheel 1. The ends facing the output shafts A and A 'each have a short bore 12, 12' respectively. A cylindrical bar 13, made of steel, for example, is housed in the bores 12 and 12 'of the two output shafts A and A'. This bar 13 has a dual role it allows, on the one hand, to stiffen the device and, on the other hand, to reduce the guide distance of the toothed wheel 1, namely the distance referenced W.

It will be noted that the bar 13 may also be of polymer, or any other material capable of guaranteeing the mechanical maintenance between the shafts A and A '. This bar is preferably cylindrical in the embodiment described above, in which it is necessary that the two shafts A and A 'are disconnected. In a variant, the bar 13 may not be cylindrical in certain applications: by for example, in the case of a permanent coupling of the two shafts A and A 'to provide a vehicle seat slide adjustment type function (a pinion / rack type mechanism being present on both sides of the seat). seat). In another alternative embodiment, the bar 13 can be directly integrated with one of the two shafts A and A ', the two shafts A and A' then being different parts and thus contributing to a additional cost of the device. Another variant of the present invention is described with reference to the drawings of FIGS. 5A to 5C, in which an attempt has been made to further reduce the bulk, and in particular the thickness of the input wheel. The operating principle is that of the modes already described above. The toothed wheel 1 is rotatably mounted on the ends of the two output shafts A and A ', coaxial, identical, and in the extension of one another, as in the previous embodiment. The electromagnet mechanism comprises a translational portion 7 and a portion 8, which is fixed relative to the frame of the mechanism (not shown). On the fixed part 8 is fixedly mounted the coil 9 of the magnetic circuit. There is shown at 15 or 15 '(see 15 in FIG. 5C more particularly) a square section orifice at the end of each output shaft A, respectively A'. Indeed, the end of each shaft is intended to accommodate a flexible tube containing a square section cable for the transmission of torque to a gearbox, when the device of the invention is, as indicated below, integrated into a mechanism 30 which distributes a motive power between several outputs. Given a relatively large mechanical torque, which may be greater than 1 Nm, the material envisaged for the output shafts must withstand high stresses; for this reason, the output shafts A and A 'are preferably made of steel in the present embodiment. However, it will be noted that there are no electromagnetic stresses on the two trees A and A ', so the material constituting these two parts may be different from the steel: the material must only meet the requirements of mechanical strength, resistance to deformation, wear, and minimal noise and vibration requirements. In a particular embodiment of the invention, to avoid a steel / steel contact between the steel output shaft A, respectively A ', and the centering bar 13', the latter can be made of polymer material, preferably of ABS type material (acronym of acrylonitrile-butadiene-styrene). When the coil 9 is supplied with electric current, the moving part 7 of the electromagnet mechanism moves towards the ring 10 of the input wheel (1) to be driven by the latter. The movable part 7 thus acts as a movable clutch plate for securing in rotation the input wheel (1) and the corresponding output shaft (A). This displacement thus makes the toothed wheel 1 and the movable part 7 integral in rotation and, consequently, makes the toothed wheel 1 and the output shaft A integral, which is secured to the movable part 7 by the effect of A key 14. Referring still to the drawings of FIGS. 5A to 5C, the fixed portion 8 of the magnetic circuit, which supports the coil, is surmounted by a peripheral ring 16, intended to facilitate the integration of said fixed part 8 in the housing of the device (not shown). A washer 17 is inserted at the contact between the output shaft A and the housing (not shown), to avoid wear of the latter. As can be seen in the drawing of Figure 5C, the washer 17 has a cutout 17a for the insertion of a key or the like which immobilizes in rotation the washer 17.

FIG. 6 shows a mechanical transmission mechanism comprising an electric actuator M, a plurality of outputs S1 to S5 between which is distributed the driving power developed by the actuator and different clutches E1, E2, E3 and E5. It is in such a transmission mechanism or motor-gear 5 that integrates the clutch device according to the present invention. In the nonlimiting example of the object of the invention, shown schematically in the drawing of FIG. 4, the mechanism comprises: a first module referenced m1, double module, with two clutches E1 and E2 (for two outputs S1 and S2), similar to any of the embodiments described above of ring-type and fixed-coil dual clutch device, - a second referenced module m2, or motor module, which includes the electric actuator M (electric motor, for example) and a single clutch module E3 for an output S3; a third module referenced m3 with two outputs S4 and S5 with a single clutch E5. The third module may be, by way of non-limiting example of the object of the invention, a slide module for controlling the translational movement of a vehicle seat on its horizontal rails. The two outputs S4 and S5 control the same function of displacement on the slideways, are each connected to a reducer placed at the level of the guide rail on both sides of the seat. Therefore, a single clutch is required for both outputs S4 and S5 of the slide module m3. Of course, the present invention is not limited to the embodiments described and represented above by way of examples; other embodiments may be devised by those skilled in the art without departing from the scope and scope of the present invention.

Claims (10)

  1. Double clutch device, which comprises a mechanical input member (1) by which the driving power is supplied, two output shafts (A, A ') coaxial and on the ends facing which the mechanical member d the inlet (1) is rotatably mounted, each output shaft (A; A ') having an electromagnetic clutch for establishing or disconnecting the drive power transmission to the output shaft, characterized in that each clutch comprises: - a magnetic circuit (5), mounted on the output shaft (A), comprising a fixed part (8) in rotation and in translation, in which is housed the electromagnet coil (9) and a moving part. (7), integral in rotation with the output shaft and movable in translation under the effect of the electromagnetic force generated when the coil (9) is energized, - said moving part (7) of the magnetic circuit (5) moving to the mechanical input member (1) to be driven by the latter when the coil (9) is energized, and thereby acting as a movable clutch plate for securing in rotation the mechanical input member (1) and the corresponding output shaft (A).   2. Device according to claim 1, characterized in that said movable part (7) of the magnetic circuit (5) has the shape of an annular plate with wide recesses (E1 to E4), so as to reduce the passage area magnetic flux between said fixed portion (8) and the surface facing the mechanical input member (1).   3. Device according to any one of claims 1 and 2, characterized in that the movable part (7) of the magnetic circuit is mounted integral with the rotation of the corresponding output shaft (A) by means of two grooves. (11) opposites.   4. Device according to claim 1, characterized in that the two output shafts (A, A ') coaxial in 5 are identical.   5. Device according to claim 1, characterized in that the two output shafts (A, A ') are coaxial, but are not identical, the male end (20') of one (A ') of the two output shafts (A, A ') being rotatably mounted in the female end (20) of the other output shaft (A) so as to decrease the axial dimension of the input mechanical member (1); ).   6. Device according to any one of claims 1, 4 and 5, characterized in that the two output shafts (A, A ') comprise a short bore (12, 12') at their end opposite, in which a single bar (13) is housed to stiffen the device and reduce the guide distance of the input mechanical member (1). 20   7. Device according to any one of claims 1 to 6, characterized in that the opposite ends of the one and the other output shaft (A, A ') have a housing of square section (15, 15' ), so as to accommodate a flexible tube containing a cable 25 of square section.   8. Device according to any one of claims 1 to 7, characterized in that the fixed part (7) of the magnetic circuit (5) is surmounted by a peripheral ring (16), so as to allow its integration 30 in a casing.   9. Device according to claim 1, characterized in that the mechanical input member (1) is a member selected from the following mechanical transmission members: input wheel, pulley, friction drive mechanism.   10. Mechanical transmission mechanism with several outputs, characterized in that it comprises: a first module (ml) constituted by a double friction cone clutch device and fixed electromagnet coils, in accordance with the present invention; any one of claims 1 to 9, a second module (m2) having an electric actuator (M) and a clutch module unit, and - a third module (m3) with two outputs (S4, S5) with a single clutch (E5). 10